Crosshead



May 30, 1933. R. w. cLlFFoRD CROSI-IEAD Filed April 25, 1952 INVENTOR Feel' WC/ Patented May 30, "1933 nocna w. cnrrronnor soHnNEcrAnY, mew Yogi: i

, caossnnnn ApplicationfiledApril 25,

p This invention relates lto the class of apparatusknown as crossheads.

More particularly, the invention relates to means for holding a wrist pinsecurely in place in a crosshead and for retracting-the pin therefroni. i

In ordinary locomotive practice, the piston rod of a working cylinder is connected to a main drive rod, which transposesrthe reciprocating motion of .thelpiston into the revolving inotion of thedrivingwheels, by means of a crosshead, the main rod being connected to the crosshead by a wrist pin which passes through the crosshead and through an eye forlned on the forward end of the rod. To, securely hold the wrist pin in place, keyways are provided in the crosshead and wrist pin, and a tapered lrey'is disposed in the keyways.

,An object of the present invention is to provide a novel and improved 'crosshead,- wrist pin and key construction.

Another object is to provide such a construction, wherein the key will serve to securely hold the wrist pin in place when in-c serted in the keyway and will serve as an extractor for'the wrist pin when` disposed in another position on the crosshead A further object is to provide such a `construction wherein the number of parts commonly used will be reduced anda saving in both space and in weight as well as in manufacturing eXpense will be effeoted. f

A further object is to provide a novel crosshead` construction embodying` ;a pin bearing for a combination lever link.

In the prior art crosshead structures have been V employed` which embodied a boss formed on one side of the body of the crosshead, ;surrounding the wrist pin bore, the boss being provided' lwithfa'vertical slot in which a. gib and a keywere disposed for holding the wrist pin in place when' assembled ino one way, and for removing the pin when assernbled in' a reverse way. The present invention obviates the use of a gib and thereby efliects a saving'in space, weight and cost. I I o' Referring in detail to the draw-ing,'wherein there is exemplified an embodiment of the 1932 .V Serial No. 607,245.

presentinvention, Figure 1 is a side elevation of a locomotive engine erossheadconjstruction elnbodying the instant tinvention; Fig; 2 isa section on the line H-H of Fig. 1; Fig. 8 is a section on the'line'HI-III of Fig.: 2; Fig. 4 is a section on'the line V-IV'ofFig. 2; Fig. 5 is a'plan view of the wrist pin; and Fig. 6 is' an end view of the VVwrist pin. IV I In the practice of the present invention, the elnbodiment shown is exelnplified as applied to al locomotive crosshead, iindica-ted generally by the numeral'l. The crosshead is of a usual type and coinprises outside and in- 'i side VVertical walls Q, each having a tapered bore`3, forined`therein,'for the reception of awrist pin, herein after to be more fully described. A cylindrical portion 4 connects i the walls 2 at the forward ends thereof, and isformed integral withthe walls and Vprovided with'a bore for the reception of an end of a piston rodf, in the usual manner. To the walls 2, are secured upper and lower shoes or walls 6, by bolts 7, which are passed V through the outside and inside walls' 2, and 7.5. through fianges 8 forined on the inner sides of the upper andv lower shoes, in the vusual inanner. Guide flanges-9 are forinedon the edges ofthcv shoes 6 in the usual inanner, and the flanges 8 are 'spaced edges, so that the outer surfaces of the walls 2,7are substantially flush with the outerv surfaces of their adjacent flanges 9;'

;A wrist pin 10 is disposed in the bores 3, transversely of the crosshead, and comprises S5 a central cylindrical portion 11, and: two frusto-conical portions 12 and 13 which fit the tapered bores of the outside and inside walls, respectively. The ,pin is provided with an'end portion 111, which extends beyond the outside wall of thecrosshead when the 'pin is in asseinbled position. The portion l'cl ex'tends across approximately onehalf-of the wrist pin, and is provided with a slot 15 having a slantingoutsi'de wall 16.

' On the outside wall 2, of the cross head, a boss 17 is'iformed. `The boss is provided with abore 18, which is aligned withthe bores 8 in the outside and inside walls, and through which bore also, the wrist pin 10 is 100 inwardly from the 80 passed. The inner portion of the bore 18 is beveled to coincide with the bore 3 of the outside wall 2. One side of theboss is extended outwardly and is provided with Vertical projections 19 and 20, in which ali'gned slots 21 and 22 are formed. The outside walls 23 and 24 of the slots 21 and 22, respectively, slant inwardly .from top. to bottom.

A key 25 is provided for the boss and pin, and when assembledinoneor the other -of its positions, eXtends either through the slots of the boss or the slot of the pin. The key is formed with an outside tapered face 26 which, when the key is extended through the slots 21 and 22`of the boss, bears against the respective slanting walls 23 .andV 24 of said slots. vThe inside face 27 of the key is straight, and in this position bears against the end of the wrist pin at 28, (Fig. 3),. The lower end of the key is provided with a slot for the insertion of a split key for retaining the key in fixed position. The key is of such thickness with relation to the slots 21 and 22 that, when the key is in the engaged position shown in Fig.v3, there is a clearance between the inside face 27 of the key and thel opposite or inner walls of said slots.

Inoperation, to securely hold wrist pin 10 in tightly engaged position in the bores 3, the key 25 is inserted through the slots 21 and 22 and upon forcing the key downwardly, its tapered face 26 will bear against the tapered surfaces 23 and 241 of the slots while its straight face 27 bears against the end of the pin 10 at 28, the downward movement of the key forcing the wrist pin inwardly so that the surfaces of the frustoconical portions 12 and 13, securely engage the surfaces of the tapered bores3 in the side walls of the crosshead. The portion 29 of the boss, i. e., the side of the boss adjacent the aforedescribed outwardly extended side thereof provided with the Vertical projections 19 and 20, extends outwardly onlyra very limited distance from the wall of theA crosshead, so that when the wrist pin is in engaged position, its end 14 extends beyond the outside of the portion 29, and its slot 15 is disposed only slightly withinthe boss as indicated at 30. It will thus be apparent that when the key 25 is inserted in the slot 15 of the pin 10, its straight face 27 will bear against the outer face 31.0f the portion 29 of the boss, and its tapered surface 26 will bear against the tapered surface 16 of the slot 15 (Fig. 4). Thus, with the key in this position, a forcing of the same downward will effect an outward movement of the pin, there being suficient clearance between the straight face 27 of the key and the opposite wall of the slot 15 to permit a slight outward movement of the pin rela- V tive to the crosshead during the said down- 'and key feature may be used either together,

as shown, orfindependently, as desired. A

slot 35 is provided in the portion 11 of the crosshead, and a key 36- is provided in the slot, the key engaging a corresponding slot (not shown) in the piston Vrod and looking the piston rod and crosshead securely to each other, in the Vusual manner. A main drive rod 37 is indicated in Fig. 1, as connected to the crosshead by means ofthewrist pin 10, the drive rod being provided in the usual manner with aneye 38 which is disposed be-:

tweenthe outside and inside walls 2 of the crosshead, and which-engages the wrist-pin 10. V

Thile there has been herenbefore described a'specific embodinient of the present invention, it will be understood that many and .various changes `in form and structure may be made withoutdeparting from the instant invention, and that all and any such changes and modifications, as fall within the spirit of the invention as defined in the appended claims are contemplated as a part of the present invention'. 1

Among the modifications contemplated by the present invention, for instance, the walls 23and 24iof the slots 21 and'22, may be made Vertical and the tapered side of the i key made vto engage a tapered end on the wrist pin atV 28. On the other hand, the tapered dwa-ll 16 of the slot 15, could be substituted by 'a' straight Vertical-wall and a taper provided onthe sidesA 31 of the'boss 17, Vand the' same result eifected. It will bev understood that while the key has been described as having one straight side and one tapered side,'t'his construction would'be, in effect, simply atapered key, and the key would act invthe different slots without any reversing'of position, in'the same manner asaforedescribed, i'e., the' word straightl in this'regard, beunderstood to imply. perpendicular to the pin'axis when in 'position. Again, the boss -17 might be made afcomplete cylinder of Aedual length `throughout and with either one wide orl two adj acent keyways. Likewise, the wrist pin portion 14 might be made larger and-be provided with either one wide or two adj acent keyways. It isobvious, however, that'when lightness and 'simplicityf'of structure? v is' sought, the construction illustrated is to be preferred.

The invention claimed and desired to be secured by Letters Patent, is:

1. A crosshead construction comprising a body portion having a pair of faces at one side thereof spaced from each other in directions both longitudinally and transversely of said body portion; a Wrist pin engaging said body portion and having faces oppositely disposed to the first said faces providing therewith two passageways for a key; and a key adapted to wedgingly fit in either of said passageways whereby wedging inovenient of the key in one of said passageways Will effect axial inoveinent of the pin in one direction to tighten the engagement of the pin and body portion, and Wedging inovement of the key in` the other passage- Way Will effect axial movement of the pin in an opposite direction to loosen said engagenent.

2. A crosshead construction comprising av body portion; a Wrist pin engaged thereby and providng therewth two key passageways spaced from each other longitudinally of the body portion; and a key engageable With each of said passageWa-ys to respectiveiy advance and retract the pin relative to the body portion, said pin being provided with an extension having a slot therethrough With a front Wall constituting thefront Wall of the said passageway permitting said reti'action, said extension providing a shoulder constituting the rear wall of the passageway for advancing the pin, and said body portion being provided with a boss having a slot With a front wall constituting the front Wall of the passageway perlnitting said advanceinent, and said boss providing a shoulder constituting the rear Wall of the passageway permitting said retraction.

ROGER VV. CLIFFORD. 

